22$ STUDIES OF NATURE. 



felvcs. If Nature, with refpefl to them, had con- 

 fined herfelf rigidly to the Law of florification, 

 they could not multiply, when paftured upon by 

 animals which continually browze on their fum- 

 mits. The fame thing takes place with regard to 

 fuch as grow along the water courfes, as reeds and 

 the aquatic trees j willows, alders, poplars, ofiers, 

 mangliers, when the waters fwell, and bury them 

 in fand, or totally fubvert them, as is frequently 

 the cafe. The (bores would remain deftitute of 

 verdure, if the vegetables, which are native there, 

 had not the faculty of re-produdion by means of 

 their own fhoots. But the cafe is different with 

 refpedt to the vegetable inhabitants of the moun- 

 tains, as palm-trees, firs, cedars, larches, pines, 

 which are not expofed to fmiilar accidents, and 

 which cannot be propagated by flips. Nay, if 

 you crop off the fummit of the palm-tree, it dies. 



We likewife find thefe fame laws of adaptation 

 and utility in the generation of animals, to which 

 we afcribe uncertainty, as foon as we perceive va- 

 riety ; or when we apprehend an approximation 

 to the vegetable kingdom by means of imaginary 

 relations, fuggefted by the perception of effects 

 common to both. Thus, for example, if fome oi 

 our more delicate plant-infecls are viviparous in 

 Summer, it is becaufe their young find, at that 

 feafon, the temperature and the food which are 

 * adapted 



